Systematic small molecule analysis using GC-MS

每个细胞都含有大量被称为代谢物的小分子。这些代谢物是细胞的基本货币；它们可以用来制造更大的分子，产生能量，还可以用作信号化合物。在单个细胞中可能有数百甚至数千种代谢物。一般来说，代谢物的组成反映了细胞的状态，例如，如果细胞高度特化，它可能产生大量的一种特定代谢物，或一系列其他特定代谢物。传统上，科学家们倾向于一次检测少量的代谢物，但我们现在能够同时测量数百种代谢物。这些信息可以作为指纹来提供有关该细胞的信息，例如，它是忙碌还是休息。这些信息还可以用来观察如果我们以某种方式改变细胞会发生什么，比如，加入一种药物，观察代谢物是如何变化的。细胞中的代谢物都通过不同的途径相互连接，这类似于伦敦地铁的地图，其中代谢物由车站表示。通过同时测量所有代谢物并观察它们如何随时间变化，我们能够更好地理解个体代谢物（监测站）是如何相互联系的。它还提供了单元格当前状态的良好快照。该建议是购买将用于同时测量大量代谢物的设备。这是一个困难的过程，因为许多代谢物在结构上非常相似，尽管它们可能具有非常不同的功能。建议使用气相色谱联用质谱法。从本质上讲，这是根据分子的化学性质和大小来分离分子的。它还提供了关于不同代谢物的丰富程度的信息。这是一个产生大量数据的专门过程。为了处理如此大量的数据和分析大量的样本，许多过程是自动化的或由计算机处理的。同样的设备也可以用于研究任何小分子，包括污染物，土壤养分和复杂的挥发性混合物。我们将使用这些设备来解决不同研究领域的一系列问题，包括：研究单个酵母细胞中代谢物之间的关系，并从这个相对简单的系统中推断，以帮助理解复杂的多细胞生物（如人类或植物）中所有细胞的工作方式。2. 干细胞提供了治愈许多目前无法治愈的疾病的潜力，但为了能够产生足够的这些细胞，需要更多地了解它们的行为方式以及是什么调节了它们的独特特性。3. 测量胰岛素生成细胞在不同条件下的代谢物变化将有助于我们了解糖尿病的发病，并可能帮助我们设计更好的药物来治疗这种疾病。4. 许多新药是通过培养细胞来生产的，为了最大限度地提高产量，了解生产这些药物如何影响培养物的行为是很重要的。5. 植物细胞壁提供了一种巨大的资源，可以作为可再生能源和新型材料加以利用。为了优化生产，需要更多关于细胞壁中化合物是如何产生的信息。6. 养分的可用性和污染物都限制了植物的生产力——通过准确地测量这些因素，就有可能提高产量。7. 嗅觉受体的结合特性仍然是一个谜；我们将能够识别表达单一嗅觉受体的单个嗅觉受体神经元的天然配体。这将对神经生物学和害虫控制策略的发展产生深远的影响。

Every cell contains very large numbers of small molecules known as metabolites. These metabolites are the essential currency of the cell; they can be used to make larger molecules, generate energy and can be used as signalling compounds. There may be many hundreds, or even thousands, of metabolites within a single cell. Generally the composition of the metabolites reflects the status of the cells, for example if the cell is highly specialised it may make a large amount of one particular metabolite, or a range of other specific metabolites. Traditionally scientists have tended to examine small numbers of metabolites at a time, but we are now in a position to measure several hundred metabolites simultaneously. This information can be used as a fingerprint to give information about that cell, is it busy or resting for example. The information can also be used to see what happens if we alter the cell in some way, by, for example, adding a drug and seeing how the metabolites change. The metabolites in a cell are all interconnected by different pathways that are analogous to a map of the London underground in which the metabolites are represented by stations. By measuring all the metabolites simultaneously and seeing how they change over time we are better able to understand how individual metabolites (the stations) are interconnected. It also gives an excellent snapshot of the current status of the cell. This proposal is to buy equipment that will be used to measure a large number of metabolites simultaneously. This is a difficult process as many metabolites are structurally very similar even though they may have very different functions. The proposal is to use Gas Chromatography coupled with Mass Spectrometry. Essentially this separates molecules based upon their chemical properties and their size. It also gives information on how abundant different metabolites are. It is a specialised process that generates a very large amount of data. In order to handle such a large amount of data and to analyse a large number of samples much of the process is automated or handled by a computer. This same equipment can also be used to study any small molecules including pollutants, soil nutrients and complex volatile mixtures. We will use the equipment to address a range of problems in diverse areas of research including: 1. Study the relationship between metabolites in the single yeast cells and extrapolate from this relatively simple system to help understand how all cells work in complex multicellular organisms such as people or plants. 2. Stem cells offer the potential to cure many diseases that are currently untreatable, but in order to be able to generate enough of these cells much more needs to be known about how they behave and what regulates their unique properties. 3. Measuring metabolite changes in insulin-producing cells under different conditions will help us to understand the onset of diabetes and may help us to design better drugs to treat the condition. 4. Many new drugs are produced by growing cells in culture and in order to maximise production it is important to understand how producing these drugs affects the behaviour of the cultures. 5. Plant cell walls offer a huge resource that could potentially be harvested for use as a renewable source of energy and novel materials. To optimise production, more information is needed on how the compounds in the cell wall are made. 6. Nutrient availability and pollutants both limit plant productivity - by measuring these factors accurately it offers the potential to boost production. 7. The binding properties of olfactory receptors remain a mystery; we will be able to identify the natural ligands of single olfactory receptor neurons that express a single kind of olfactory receptor. This will have far-reaching implications for neurobiology and for the development of pest control strategies.